Citations

Abstract OBJECTIVE AND IMPORTANCE: Magnetic resonance imaging (MRI) is the imaging modality of choice for brain tumors and other lesions of the central nervous system. However, this procedure is contraindicated in patients with orbital metallic foreign bodies. In such cases, the usual clinical strategy is to manage the patient without the benefit of MRI scans and, instead, to rely on less sensitive imaging modalities in particular computed tomographic scanning. CLINICAL PRESENTATION: Two patients, one with a posterior fossa mass and one with suspected central nervous system lymphoma, were seen at our institution. MRI scanning was recommended, but had been precluded in both patients by the presence of metal fragments in the orbit. INTERVENTION: In each case, the orbital foreign body was successfully localized and removed. Postprocedure computed tomographic scanning confirmed complete removal. MRI scanning was then performed without difficulty. The first patient underwent posterior fossa craniotomy and removal of the tumor, which proved to be a medulloblastoma. The second patient was found to have evidence of lymphoma in the cranial base and meninges and was treated with radiotherapy and systemic and intrathecal chemotherapy. MRI scanning provided superior diagnostic information and spared both patients the risks and discomfort of myelography and exposure to ionizing radiation from multiple computerized tomographic scans. CONCLUSION: Two patients with central nervous system tumors underwent removal of a metal fragment in the orbit for the specific purpose of facilitating MRI scans. This is a practical, straightforward concept, which should be considered when MRI scanning is needed for optimal patient management.

The National Heart, Lung, and Blood Institute (NHLBI) convened a conference call working group, consisting of experts in stroke and cerebrovascular biology on January 28, 2005. The purpose of this working group was to develop a prioritized set of recommendations for NHLBI to establish a focused and comprehensive set of research activities in cerebrovascular biology and disease. Three thematic areas of research emerged: (1) molecular and cellular neurobiology of cerebral blood vessels, focusing on genomics and proteomics, neurovascular signaling and cerebrovascular embryogenesis, development and plasticity; (2) resource development, involving the development of new methodological approaches for normal and altered function of the neurovascular unit, collaborative research, and training in cerebrovascular pathobiology; and (3) cerebrovascular diseases and translational approaches, addressing vascular mechanisms of disease, the role of risk factors, importance of biomarkers with the ultimate goal of developing new treatments.

The Minnesota Child Development Inventory (MCDI) was used to describe the developmental status of 59 children before the start of kindergarten. Three years later children were classified in one of four categories, based on the amount of supplemental reading instruction necessary during the three-year period. A number of variables from the MCDI were highly correlated with this continuum of difficulty in mastering reading, with parental report of the child's general development and knowledge of letters and numbers being most significant. Significant correlations with group achievement tests also were obtained. The findings should encourage the inclusion of parent reports by persons using or constructing preschool screening measures.

A method is presented for analyzing phonatory instabilities that occur as modulations of fundamental frequency (f 0 ) and sound pressure level (SPL) on the order of 0.2 to 20 cycles per second. Such long-term phonatory instabilities, including but not limited to traditional notions of tremor, are distinct from cycle-to-cycle perturbation such as jitter or shimmer. For each of the 2 parameters (f 0 , in Hz, and SPL, in dB), 3 frequency domains are proposed: (a) flutter (10–20 Hz), (b) tremor (2–10 Hz), and (c) wow (0.2–2.0 Hz), yielding 6 types of instability. Analyses were implemented using fast Fourier transforms (FFTs) with domain-specific analysis parameters. Outputs include a graphic display in the form of a set of low-frequency spectrograms (the “modulogram”) and quantitative measures of the frequencies, magnitudes, durations, and sinusoidal form of the instabilities. An index of a given instability is developed by combining its duration and average modulation magnitude into a single quantity. Performance of the algorithms was assessed by analyzing test signals with known degrees of modulation, and a range of applications was reviewed to provide a rationale for use of modulograms in phonatory assessment.

More than 30 years ago, Darley, Aronson, and Brown (1969) proposed clinicoanatomic correlations for seven perceptual types of dysarthria. These correlations have not been systematically re-examined even though imaging technologies developed in recent years provide the means to do so. This review considers data from published imaging studies as well as data from selected medical interventions to evaluate the current state of knowledge that relates lesion site to the nature of a speech disturbance. Although the extant data are not sufficient to allow a complete evaluation of the seven types of dysarthria described by Darley et al., relevant information has been reported on lesions of the pyramidal pathway, extrapyramidal pathway, and cerebellum. In general, the results are best explained by an equivalence mode of brain-behavior relationship in which a type of dysarthria is associated with a lesion in one of two or more brain structures. Criteria also are proposed for future studies of clinicoanatomic relationships in neurogenic communication disorders.